It seems like the upcoming video game Gotham Knights will be outside of the established Batman Arkham canon. While I have not seen anyone confirm this, there are several clues to this being true, looking at the details from the announcement trailer:

1. Mr. Freeze is still evil, despite changing in Arkham Knight. 
2. Robin looks a lot younger than he was in Arkham Knight. 
3. Jason Todd's face scar looks different. 
4. The voice actor for Batman indicates a much younger Batman

The above are under the assumption that this game would take place after Batman Arkham Knight, which would have to be the case if it were canon, as Red Hood exists in this game. 

Now, if WB Games Montreal wanted to do there own game very disconnected from the Arkham series, that would be okay. But there are several things about this game that tie it to the Arkham games:

• The gameplay looks very similar.
• The main characters are exactly Batman's allies from the previous games, no more and no less. 
• The premise of the game is that Batman died in an explosion. This is exactly what happens at the end of Batman Arkham Knight

Now, there would not be a lot of work in fixing this game so that it is within the Arkham cannon. All that would need to be done is remove anything that contradicts the previous games. I am even willing to let number 4 from my list above slide, I am not unreasonable. 

By signing this petition, you indicate to WB Games Montreal that you will not tolerate this new canon, when this game screams out to be put in the Arkham canon. That is, by signing this petition, you indicate that you WILL NOT BUY GOTHAM KNIGHTS until the game is put into the Arkham canon.